Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Condensed Consolidated Statements of Comprehensive Income (unaudited) [Abstract]
Net earnings	$ 15,518	$ 11,886
Other comprehensive income (loss), net of tax:
Net foreign currency translation adjustment	541	1,255
Net change in postretirement benefit plan, net of taxes of $(5) and $1 for the three months ended March 31, 2017 and 2016	10	(4)
Other comprehensive income	551	1,251
Comprehensive income	$ 16,069	$ 13,137

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature, attributable to parent entity.

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